import com.sun.org.apache.xpath.internal.operations.String;

import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User:DELL
 * Date:2024-10-25
 * Time:23:12
 */
public class Test{
    public static java.lang.String fun(String str) {
        String string="";
        for (int i = 0; i < str.length(); i++) {
            char ch=str.charAt(i);
            if(!java.lang.String.contains(ch+"")){
                String+=ch;
            }
        }
        return String;
    }
    public static void main(String[] args) {
        Scanner scan=new Scanner(System.in);
        while (scan.hasNextLine());
        java.lang.String s=scan.nextLine();
        java.lang.String ret=fun(s);
        System.out.println(ret);
    }
}
